Table 1.
Demographics and characteristics of patients separated by PLN count
| Variables | PLNs ≤ 2, n (%) (n = 211) | PLNs > 2, n (%) (n = 137) | P |
|---|---|---|---|
| Gender | |||
| Male | 152 (72.0) | 113 (82.5) | 0.029 |
| Female | 59 (28.0) | 24 (17.5) | |
| Age (years) | |||
| ≤45 | 109 (51.7) | 74 (54.0) | 0.742 |
| >45 | 102 (48.3) | 63 (46.0) | |
| Time interval (from initial treatment to recurrence) | |||
| Median (range) | 21.0 (5.1–238.4) | 18.9 (5.9–194.8) | – |
| Follow-up | |||
| Median (range) | 31.3 (4.1–198.2) | 29.0 (4.1–167.8) | – |
| Recurrent N stage # | |||
| N1 | 177 (83.9) | 75 (54.7) | <0.001 |
| N2 | 8 (3.8) | 6 (4.4) | |
| N3 | 26 (12.3) | 56 (23.6) | |
| Maximal diameter of LNs (mm) | |||
| ≤20 | 153 (72.5) | 101 (73.7) | 0.380 |
| >20 | 58 (27.5) | 36 (26.3) | |
| Bilaterality | |||
| Unilateral | 208 (98.6) | 124 (90.5) | <0.001 |
| Bilateral | 3 (1.4) | 13 (9.5) | |
| ENE | |||
| ENE (−) | 127 (60.2) | 87 (63.5) | 0.574 |
| ENE (+) | 84 (39.8) | 50 (36.5) | |
| Lower neck involvement | |||
| No | 186 (88.2) | 82 (59.9) | <0.001 |
| Yes | 25 (11.8) | 55 (40.1) | |
| Surgical methods | |||
| SND | 153 (72.5) | 89 (65.0) | 0.153 |
| RND | 58 (27.5) | 48 (35.0) | |
| Postoperative treatment | |||
| No | 166 (78.7) | 86 (62.8) | 0.002 |
| Yes | 45 (21.3) | 51 (37.2) | |
| Presurgical EBV DNA value (copies/mL)* | |||
| ≤4000 | 81 (73.9) | 96 (73.6) | 1.000 |
| >4000 | 93 (26.1) | 75 (26.4) | |
#Recurrent N stage was evaluated according to the AJCC TNM staging system (8th edition) for NPC. *Plasma EBV DNA test was not performed in patients treated before 2007. AJCC TNM, American Joint Committee on Cancer tumor-node-metastasis; EBV, Epstein–Barr virus; ENE, extranodal extension; PLN, positive lymph node; RND, radical neck dissection; SND, selective neck dissection.